| Figs?Ficus carica L.?are also known as milk berries and azaleas.Their edible parts are aggregated fruits made by expanding the torus.With high nutrition and high medicinal properties,it is an important crop for the consumption of fresh fruits and dried products around the world.It is known as"the patron saint of human health in the21st century".However,the development of the fig industry in China is still in its infancy,and large-scale planting and industrialization operations have not been formed.At the same time,the fresh fruit harvest period of figs is relatively short,only 7-10 days.However,dried figs can be stored for 6-8 months.In order to make efficient use of fig resources and prolong the fruit supply period,this study uses figs as raw materials,and comparatively analyzes the effects of different storage conditions?4?,-20??on the quality of figs.The influence of fig texture quality and volatile components;at the same time,the low-sugar fig jam was developed using-20?fig as raw material.It was expected to provide theoretical basis and data support for the comprehensive utilization of figs,and promote the development of fig planting area and economic benefits.The main findings were as follows:?1?The effect of different storage conditions?4?,-20??on the quality of figs was studied.The results showed that there were no significant differences in total sugar,crude protein,and crude fat of figs treated at 4?and-20??P>0.05?;there were significant differences in water content,soluble solids,total acid,and vitamin C?P<0.05?.Among them,the contents of water,soluble solid,total acid and vitamin C in figs under 4?storage were 84.65±0.07 g/100g,15.03±0.21 Brix,0.17±0.04 g/100g,?5.11±0.45?×10-4 g/100g,respectively.The contents of water,soluble solid,total acid and vitamin C in figs under storage at-20?were 85.59±0.13g/100g,13.67±0.06Brix,0.12±0.01g/100g and?3.68±0.40?×10-4 g/100g,respectively.In addition,both contain 17 amino acids,except for tryptophan?Trp?,including 7 essential amino acids,2 umami amino acids,8 non-essential amino acids,and there is no significant difference in total amino acid?TAA??P>0.05?.In addition,the storage temperature of 4?and-20?can effectively inhibit the activity of PPO and POD enzymes,but the effect of inhibiting LOX enzymes is not obvious.In general,the storage conditions of 4?and-20?had similar effects on the storage quality of figs.?2?Changes in the quality of figs after different drying?hot air,vacuum,vacuum freezing?methods.Using 4°C fig as raw material,the quality of the dried figs treated by three different drying methods was analyzed using electronic eye,texture analyzer and gas chromatography-mass spectrometry?GC-MS?,etc.The results showed that the dried figs obtained by the three drying methods can be effectively distinguished using the electronic eye when their moisture content was about 5%;Vacuum freeze-drying took the longest time,which was 2.75 times of hot air drying,and 3.14 times of the vacuum drying.The texture analysis results showed that the hardness value of the dried figs obtained by hot air drying was 1286.41 g and the fracturability value was 1074.82 g,springiness value was 0.99 mm,cohesiveness value was 0.78%,chewiness value was985.36 m J,resilience value was 0.34 mm,both greater than vacuum drying and vacuum freeze dried fig;The volatile component analysis results showed that totally 52 kinds of volatile components were detected in the three kinds of dried figs,mainly aldehydes,alcohols,acids,hydrocarbons,which accounted for 90.49%-91.26%of the total volatile components.Meanwhile,33 of them were detected in hot-dried dried figs,32 in vacuum dried figs,and 29 in vacuum freeze-dried dried figs.There were 15 kinds of common volatile components detected in all three dried figs.The major volatile components were benzaldehyde,which took part 38.97%in hot air method,39.03%in vacuum dried method,and 46.49%in vacuum freeze-dried.Besides,psoralen was detected only in the dried figs of hot air drying.?3?Development of low-sugar fig jam.Using-20°C fig as raw material,in order to develop jams with less sugar,the formula of low-sugar fig jam was optimized by single factor-response surface test and its nutritional composition was determined.The results showed that the low-sugar fig jam added 17%rock sugar powder,0.6%citric acid,0.8%pectin,and 2%honey.The jam had the special aroma of figs and honey,bright color,good spreadability,uniform and fine structure,and no other odors or foreign bodies.At the same time,the nutritional components of the jam under these conditions were:total sugar 23.67 g/100g,total acid 0.69 g/100g,crude protein 0.80g/100g,crude fat 0.09 g/100g,coarse ash 0.50 g/100g and so on.And within 6 months of the jam,the total number of colonies,coliforms and molds were not detected,which met the relevant national standards. |
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